cnn chief medical correspondent, dr. sanjay gupta, caught up with walker and learned how the musician overcame his fear. >> reporter: clay walker began his life trying to overcome modest roots and make it on the big stage. years later, he was a bona fide country music star. almost as soon as he made it big, that dream started to fall apart. >> my hands, trying to play the guitar, i couldn't hold a guitar pick in my hand. i was devastated. i knew that something of wrong near logically. >> reporter: that neural logical problem was multiple sclerosis. according to the first doctor he visited, his life was effectively over. >> he said that i would be in a wheelchair in four years and that i would be dead in eight. >> reporter: walker spent years huddled with fily and gripped by fear. then he made an emotional turn. he wanted to share information about his disease with his fans. he first hunted for an expert about his particular disease called relapsing remiticm.s. then walker made a holistic change to his life, a new diet, e